Authors: Anita Cochran, Harold Levison, Peter Tamblyn, Alan Stern, & Martin Duncan

Status: Astrophysical Journal Letters , 503, L89.

Abstract: The limiting magnitude of the HST data set used by Cochran et al. (1995) to detect small objects in the Kuiper belt is reevaluated, and the methods used are described in detail. It is shown, by implanting artificial objects in the original HST images, and re-reducing the images using our original algorithm, that about 50% of the objects with V=28.4 and in known orbits are found. This value is statistically the same as the value found in the original analysis. In the same data in which these faint objects are detected, we find that the number of false detections brighter than V=28.8 is less than one per WFPC2 image. We show that the model of the signal-to-noise ratio of this data developed by Brown et al. (1997) does not represent the real HST data and that their conclusions are therefore invalid.

Click here for an encapsulated postscript file of this paper.